Využití odstupňované sklizně u primárně aromatických odrůd révy vinné

This bachelor thesis deals with acids. In the Literary section, individual acids in grapes and wine were summarized. Also, the possibilities of acid reduction or increase were discussed. Furthermore, it has been described how individual acids change during maturation and how they affect the stability and taste of the resulting wine. Finally, I analyzed the possible defects that may be related to acid shortages or excesses. In the Practical part I deal with the description of the experiment and the evaluation of the individual results. In an attempt, I tried several ways to use the acid reserve. Individual variants were: addition of acid reserve in the form of must before fermentation, or mashing of control and acid reserve in different ratios. The parameters of the resulting wine were measured and processed as well as the results of the sensory evaluation. From the results I can say that pre-harvest utilization is a way to increase the acid content of wine

Formation, Losses, Preservation and Recovery of Aroma Compounds in the Winemaking Process

A wine’s aroma profile is an important part of the criteria affecting wine acceptability by consumers. Its characterisation is complex because volatile molecules usually belong to different classes such as alcohols, esters, aldehydes, acids, terpenes, phenols and lactones with a wide range of polarity, concentrations and undesirable off-aromas. This review focused on mechanisms and conditions of the formation of individual aroma compounds in wine such as esters and higher alcohols by yeast during fermentation. Additionally, aroma losses during fermentation are currently the subject of many studies because they can lead to a reduction in wine quality. Principles of aroma losses, their prevention and recovery techniques are described in this review